利用杠杆撬重物，省力的方式是（） A.动力臂大于阻力臂 B.动力_爱下问搜题

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问题单项选择题

利用杠杆撬重物，省力的方式是（）

A.动力臂大于阻力臂

B.动力臂小于阻力臂

C.动力臂等于阻力臂

D.B和C都正确

答案

参考答案：A

单项选择题

某种汉堡包每个成本4.5元，售价10.5元，当天卖不完的汉堡包即不再出售。在过去十天里，餐厅每天都会准备200个汉堡包，其中有六天正好卖完，四天各剩余25个，问这十天该餐厅卖汉堡包共赚了多少元（）

A.10850

B.10950

C.11050

D.11350

填空题

用方框中所给单词的适当形式填空，使短文完整正确。（每个单词限用一次）

too much, bad for, important, healthy, energy, kinds, however, mainly, breakfast, develop

     As we all know, we are what we eat. So it's very l        for us to have healthy eating habits.2         , bad eating habits are still very common among us students.  Some of us often go to school without3        ; some like to have snacks; some others'are particular(挑剔的)  about food; and still some eat ordrink 4         .
All these bad habits will surely be 5        ,our health. To keep 6        , we should have different 7         of
healthy diets, which 8      _ include proper amounts of fish, meat, vegetables, fruit as well as main food.
Besides, we'd better have meals regularly(右规律地).In my opinion, we should try to 9        healthy eating habits to build up a strong body.  Only in this way can we have enough10       to study better.